Winged ants (Hymenoptera: Formicidae) presence in twigs on the leaf litter of Atlantic Forest

Abstract: In the leaf litter, ants have various nesting resources available, such as live or dead trunks, twigs, leaves, fruits and seeds. On the twigs, there are adults and immature individuals, but also the queen and winged. The production of wings requires time and energy from the colony. The objective of this study was to investigate the presence of winged in ant colonies in twigs on the leaf litter. Our prediction is that the richness and abundance of winged in twigs are the greatest in rainy months. We collected all twigs with ants in 552 plots with 16 m2, totaling 8,832 m2 of leaf litter, in areas located in the Brazilian Atlantic Domain. We compared the species richness and the number of colonies with and without winged, as well as the number of winged over a year. In total, we collected 1,521 twigs with colonies belonging to 92 species of ants. The rate of twigs with winged was low, about 12%. In colonies with winged, the total number of twigs, species and amount of winged does not differ between the months considered dry and rainy. The majority of winged species are leaf litter dwellers, such as Linepithema neotropicum, recorded with the highest amount of winged irrespective of the period. Arboreal species colonized 15% of the twigs and, in 1/3 of these species, winged were recorded as part of the composition of the colony. Although winged represent a small percentage of the colony in twigs, our results indicate that this feature is important for the life cycle of 44% of the species that occupy twigs, considering that winged are fundamental for the dispersion of the colony.

摘要：在地表枯落物层（leaf litter）中，蚂蚁拥有多样的筑巢资源，包括活树干、枯树干、细枝、叶片、果实与种子。细枝内不仅栖息着成虫与未成熟个体，还可能存在蚁后及具翅个体（winged）。翅的发育需要蚁群投入大量时间与能量。本研究旨在调查巴西大西洋森林域（Brazilian Atlantic Domain）内，地表枯落物层中细枝内的蚁群具翅个体存在情况。本研究预测：细枝内具翅个体的物种丰富度与个体丰度在雨季达到峰值。我们在该区域的552块面积为16平方米的样方内收集所有携带有蚂蚁的细枝，总调查枯落物面积达8832平方米。我们对比了携带有具翅个体与未携带有具翅个体的蚁群的物种丰富度、蚁群数量，并分析了全年具翅个体的数量动态。本次研究共收集到1521根携带有蚁群的细枝，隶属于92种蚂蚁。其中携带有具翅个体的细枝占比仅约12%。在携带有具翅个体的蚁群中，其细枝总数、物种数及具翅个体数量在旱季与雨季之间均无显著差异。多数携带具翅个体的物种为枯落物栖息类群，例如新热带臭蚁（Linepithema neotropicum），无论在哪个时期，该物种的具翅个体数量均为最高。树栖类群定植了15%的细枝样方，其中1/3的树栖物种的蚁群中曾记录到具翅个体。尽管细枝内的具翅个体仅占蚁群的一小部分，但我们的研究结果表明，该特征对占据细枝的44%的物种的生活周期至关重要——鉴于具翅个体是蚁群扩散的核心要素。